textproduct: Quad Cities

KEY MESSAGES

- A significant winter storm will impact the area tonight through Saturday night. Probabilities are high (80-90%) for at least 8 inches of snow over much of the area. Probabilities for 12+ inches of snow are high (70-80%) north of a Sigourney, IA to Aledo, IL line. Winter storm warnings continue for the entire area.

- Below normal temperatures will be seen next week with a chance of snow on Monday.

UPDATE

Issued at 745 PM CST Fri Nov 28 2025

The 00z UA sounding at DVN shows a rapidly saturating air mass above 700mb, with a wetbulb temperature profile that shows we'll be seeing a deep dendritic profile once fully saturated. This seems to match the depiction on radar, showing numerous areas of 25 to 30 Dbz over Iowa. I have noticed reports of 1/2 mile visibility in moderate snow as close by at Marshalltown Iowa, with MPING and obs showing the band extending along and north of I-80 is reaching the ground. This saturation process is not taking long, and an accumulating snow should begin in our west in the next hour, and several inches by midnight remain a good possibility west of I-380. Our current headlines are well supported by analysis and radar/roads trends. This had the look of a major winter storm, and we expect impacts to reach winter storm warning levels during the overnight hours tonight.

If you are traveling, be aware that conditions will deteriorate as the night progresses, even in Illinois where it will be mainly after midnight.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 128 PM CST Fri Nov 28 2025

Clouds will continue to increase late this afternoon and evening ahead of the storm.

Forecast profiles of the atmosphere show a very deep column of dry air that will have to saturate before the snow reaches the ground. However, the forcing and moisture above the dry layer is impressive so it will not take long for top-down saturation to occur.

That being said areas along/west of I-380 should see snow quickly develop between 8 and 10 PM. Snow will then overspread the remainder of the area through sunrise Saturday.

Based on the HREF, the initial shot of warm advection snow has a medium to high probability (60-80%) of seeing snowfall rates of 1 inch/hour at times through sunrise Saturday.

On Saturday, the main system snow settles in across the area. Snowfall rates generally look to be 0.5-0.7 inches/hour. The exception will be during the late afternoon/early evening when the main low moves through the area. During this time frame, snowfall rates of 1-1.5 inches/hour will be possible. During the passage of the low, the snow will become mixed with rain and may briefly change over to all rain along/south of a Keosauqua, IA to Macomb, IL line.

The character of the snow will change during the event. It will initially start out as a fairly dry snow tonight but will become more wet during the day on Saturday. Saturday night the snow will trend back to being dry again and slowly end from west to east after midnight.

Winds will be increasing to 15-25 mph tonight and will continue during the day Saturday. The potential is there for wind gusts of 30- 35 mph at times during the day Saturday. There will be a lull in the winds during the passage of the low in the 3-8 PM time frame. After the low passes, winds will again increase to 15-25 mph with gusts of 30-35 mph possible Saturday night. Drifting snow is possible Saturday night as the character of the snow becomes drier.

As for amounts, they have trended a bit higher. It is not uncommon for early and late season events to over-perform on snowfall amounts because moisture is more plentiful.

Right now it appears that widespread 10-15 inch accumulations are possible north of an Ottumwa, IA to Galesburg, IL line. South of this line, 7-10 inch amounts are possible.

This storm has a high probability (>80%) of being in the top 3 heaviest snowfalls for November, depending upon the location.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 128 PM CST Fri Nov 28 2025

Sunday Assessment...A certainty (>99%) of below normal temperatures

The slight southward shift in the track of the pivoting storm system means light snow will linger east of the Mississippi Sunday morning before ending. Windy conditions through the day will keep wind chills in the single digits and teens.

Sunday night through Friday Assessment...Very high confidence (>90%) of below normal temperatures

Polar air will overspread the Midwest in the wake of the departing storm system and essentially remain in place for the week.

Single digit lows will be seen Sunday night and Monday night across the area. However, winds will be light so wind chills will be close to the actual ambient temperature.

All global models bring a weak upper level disturbance through the area Monday afternoon/evening and show this with 30-50% pops. The system is moisture starved but the forcing is good. Thus there should be a quick shot of light snow Monday afternoon/evening for areas generally south of Highway 30. Early estimates suggest a dusting of accumulation in the Highway 30 corridor with amounts approaching an inch south of a Sigourney, IA to Aledo, IL line.

A very weak system is progged to move through the area on Wednesday which will allow a brief warm-up in temperatures. The models disagree on track and timing but agree that the system is moisture starved. As we get closer to the event some better resolution may result in low snow chances being generated.

Outside of these two snow chances, the remainder of the week looks to be dry and colder than normal.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1200 AM CST Sat Nov 29 2025

Poor flying conditions will continue at least into Saturday evening as a potent winter storm continues to bring heavy accumulating snow and LIFR conditions to the region. Dry air appears to be holding onto VFR conditions south of Interstate 80 as of TAF issuance, but we expect these conditions to eventually deteriorate.

Snowfall rates with this system will most likely be around 0.5 to 0.75 inches per hour during the duration of the winter storm, but rates of 1 to 1.5 inches per hour are possible early Saturday morning and again Saturday afternoon. Models don't really favor a wet vs. a dry snow, although a drier snow is likely at the start of the event. Winds will also be a factor as gusts between 20 to 30 knots are possible at times, so some blowing snow may need to be added to the forecast.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Winter Storm Warning until 6 AM CST Sunday for IAZ040-051-052- 063-064-076-077-087-088. Winter Storm Warning until 6 AM CST Sunday for IAZ041-042-053- 054-065>068-078-089-098-099. IL...Winter Storm Warning until 6 AM CST Sunday for ILZ001-002-007- 009-015>018-024>026-034-035. MO...Winter Storm Warning until 6 AM CST Sunday for MOZ009-010.